oss-security - CVE request for Calibre

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Date: Tue, 1 Nov 2011 21:43:04 -0400
From: "Jason A. Donenfeld" <Jason@...c4.com>
To: oss-security <oss-security@...ts.openwall.com>
Subject: CVE request for Calibre

Hello,

There are 5 separate vulnerabilities with the calibre SUID mount
helper, with each possibly requiring a different CVE, or perhaps two
can be clumped together:

These vulnerabilities concern /src/calibre/devices/linux_mount_helper.c
http://bazaar.launchpad.net/~kovid/calibre/trunk/view/head:/src/calibre/devices/linux_mount_helper.c

1. Ability to create root owned directory anywhere. The mount helper
calls mkdir(argv[3], ...) on line 48.

2. Ability to remove any empty directory on the system. For example, line 172.

3. Ability to create and delete
user_controlled_dir/.created_by_calibre_mount_helper anywhere on the
filesystem, lines 55 and 165.

4. Ability to inject arguments into 'mount' being exec'd. On lines 78,
81, and 83, the final two arguments to mount are user controlled. On
lines 1033, 106, 108, 139, and 141, the last argument to unmount/eject
is user controlled. The "exists()" check can be subverted via race
condition or by creating an existing file in the working directory
with a filename equal to the desired injected argument.

5. Ability to execute any program as root. The mount helper makes use
of execlp on lines 78, 81, 83, 103, 106, 108, 139, and 141, and the
first argument does not start with a / character. Because of this,
execlp will search PATH for the executable to run. PATH is user
controlled, and thus it is trivial to write a program that spawns a
shell and give it "mount" as a filename, and direct PATH to its
directory.

These have been reported in bug 885027 for the Calibre project.

Thanks,
Jason

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